Error trying to append user to groups user collection

[Access]

Here is my function to change a users permission level in the database.
This relates to an Access database secured using Access security.
This function is called if the end user changes a staff members access.
The two options are 1 = Normal User and 2 = Super User.

It gets down to the line
..Users.Append usr

and generates an error 3129 Invalid Operation.
Public Function changePermissionLevel(strUsername As String,
bytOldPermissionLevel As Byte, bytNewPermissionLevel As Byte) As
Boolean
On Error GoTo err_changePermissionLevel
Dim ws As Workspace
Dim usr As User
Dim grp As Group

'if there is something to do
If bytOldPermissionLevel <> bytNewPermissionLevel Then
Set ws = DBEngine.Workspaces(0)
'remove existing group access
For Each grp In ws.Groups
'if it's one of my groups
If grp.Name = "Update Data Users" Or grp.Name = "Admins"
Then
'remove the user from the group
For Each usr In grp.Users
If usr.Name = strUsername Then
grp.Users.Delete strUsername
End If
Next usr
End If
Next grp

'reset permission access
If bytNewPermissionLevel = 1 Then
With ws.Groups("Update Data Users")
Set usr = ws.Users(strUsername)
.Users.Append usr
End With
Else
With ws.Groups("Admins")
Set usr = ws.Users(strUsername)
.Users.Append usr
End With
End If
End If

err_changePermissionLevel:
If Err = 0 Then
changePermissionLevel = True
Else
changePermissionLevel = False
End If
End Function

[MGFoster]

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You have to create a new User in the group before appending to the
group's Users collection.

Replace this:

Set usr = ws.Users(strUsername)
.Users.Append usr

with this:

.Users.Append .CreateUser(strUserName)

--
MGFoster:::mgf00 <at> earthlink <decimal-point> net
Oakland, CA (USA)

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Access wrote:

Here is my function to change a users permission level in the database.
This relates to an Access database secured using Access security.
This function is called if the end user changes a staff members access.
The two options are 1 = Normal User and 2 = Super User.

It gets down to the line
.Users.Append usr

and generates an error 3129 Invalid Operation.
Public Function changePermissionLevel(strUsername As String,
bytOldPermissionLevel As Byte, bytNewPermissionLevel As Byte) As
Boolean
On Error GoTo err_changePermissionLevel
Dim ws As Workspace
Dim usr As User
Dim grp As Group

'if there is something to do
If bytOldPermissionLevel <> bytNewPermissionLevel Then
Set ws = DBEngine.Workspaces(0)
'remove existing group access
For Each grp In ws.Groups
'if it's one of my groups
If grp.Name = "Update Data Users" Or grp.Name = "Admins"
Then
'remove the user from the group
For Each usr In grp.Users
If usr.Name = strUsername Then
grp.Users.Delete strUsername
End If
Next usr
End If
Next grp

'reset permission access
If bytNewPermissionLevel = 1 Then
With ws.Groups("Update Data Users")
Set usr = ws.Users(strUsername)
.Users.Append usr
End With
Else
With ws.Groups("Admins")
Set usr = ws.Users(strUsername)
.Users.Append usr
End With
End If
End If

err_changePermissionLevel:
If Err = 0 Then
changePermissionLevel = True
Else
changePermissionLevel = False
End If
End Function